Bit-holder for mining-machines.



N. D. LEVIN.

-B|T HOLDER FOR MINING MACHINES.

APPLICATION FILED 1AN.BII909.

Patented May18, 1915.

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BIT-HOLDER FOR mrmie-rascnrnns.

mantra.

Specification of Letters Extent.

itatenteel 18, 12915.

Application tiled January 23,1909. Serial No. 471,298.

T012 whom it may concern:

lie it known that T, NILS D. LEVIN, a citizen of the United States, residing at C- lumbus, in the county of Franklin and State of @hio, have invented certain new and useful improvements in Bit-Holders :t'or lllining-h'iachines, of which the following is a specification, reterence being had therein to the accompanying drawing.

This invention relates to improvements in devices for attaching bits or cutters to the cutting chains or wheels of mining machines. 4

The object of the invention is to furnish a simple and effective, and at the same time readily adjustable means for holding the bits.

Tn the drawings 'fi igure 1 is a plan view of: a section of chain showing one hit or cutter attached. Fig. 2 is an elevation of the section of chain shown in Fig. i. Fig. 3 is a sectional view through the line -50 of Fig. 1. j

it do not wish to confine myself to. the chain shown in the drawings which is used merely for the purpose of illustration.

A represents one of a series of links of the mining machine chain and is adapted. to carry the cutter or hit D.

B-B andC-C are other links connected to the link A by the pins 6 and c.

E is a boss or lug on the link A and is either cast or forged integrally therewith or secured in any other suitable or preferred manner.

F is a hole extending through the link A and the boss E at an angle to the line of motion of the chain, and is formed to receive the shank of the bit. The boss lid is provided with a hole G at an angle to the hole F and adjacent thereto. This hole is tapering in form and is adapted to receive a key or cotter H which is similarly tapered. One edge of this key is provided with a series of longitudinal teeth Til. The hole G is so disposed in. relation to the hole F that as the tapered key H is forced into it the longitudinal teeth of the key will he brought into engagement with similarly disposed teeth h: formed on the shanks of the bit, and adapted to mate with the teeth of bit shank is also provided with other teeth K on the side opposite to the teeth h: so that the bit may be attached to the chain with the working point TJ prothe key. The

in either direction to correspond with the proposed direction of motion of the chain.

WV hen it is desired to adjust or replace the hit, assuming it to be in position as shown in the drawings, it is only necessary to drive back the wedge shaped key H, thus permitting the disengagement of the teeth H, and K or K and leaving the hit tree to be adjusted in the hole F or entirely removed if desired. ,Whenthe bit has been adjusted or replaced, as the case may he, the key it is driven back into the hole G, the converging sides of which force the teeth of the key into engagement with the teeth of the hit, thus securely locking the latter in position.

t will he observed that there are importaut advantages incident to the wedge in the manner shown and described. The wedge lies substantially parallel t0 the lines of movement and its larger end is foremost. In the operation of a mining machine it frequently happens that the parts adjacent to the cutters come in contact with external objects, such as lumps of coal, pieces of slate, etc, which may accidentally fall into the kert or otherwise come into the path of the moving parts. The arrangement of the wedges is such that accidental contact of the wedges with these external olojects will serve to drive the wedges more firmly into their places, lit will be apparent that this result cannot be obtained with any other arrangement or with any other positions of the wedges. llt will furthermore be observed that each hit shank contacts at its forward and rear edges directly with the walls of the aperture in which it is located so that the stresses of cutting are transmitted directly to the heavy bit-carrying parts independently of any intermediate holding devices such as set screws, latches, wedges, etc.

What ll claim is,

The combination in a mining machine hit and holder, of a bit carrying element having an inward extending aperture for receiving a bit shank and a second aperture at one side of the first eating therewith, the first aperture being at an angle to the line of motion of the carrying element and the second aperture being substantially parallel with the said line,

the location of V aperture but communia hit having its shank positioned in the first or shank receiving aperture, and a rearward tapering friction held wedge in the second aperture, one side of the wedge being in forced engagement with the shank of the bit and the opposite side being in forced engagement with the aperture Wall opposite external objects will tend to force the wedge into firmer en In testimony whereof I 1n .presence of two witnesses.

Witnesses gagement with the bit shank. 1O

affix my s1 gnature,

NILS D. LEVIN.

H. B. ALEXANDER,

H. W. C

RUM LEY. 

